This invention relates to a device for simultaneously reducing torque and vibration caused by an off-center impact of a ball and the face of a racquet. More particularly, the invention is directed to a device for simultaneously reducing wrist and elbow strain and minimizing errors in the trajectory of the ball as it rebounds off the racquet face. The invention is suitable for use with all types of racquets and paddles used in various sports.
Conventional racquets normally comprise a racquet face of strings into which the ball to be hit impacts. These racquets include an elongated rod or shaft which is attached to the outer perimeter of the racquet head so as to provide a handle. Although the conventional racquet has in the past functioned satisfactorily when a ball hits the center of the racquet face, it inherently possesses a number of substantial drawbacks when a ball strikes the racquet face outside of the central axis of the racquet.
The greatest drawback of the conventional racquet is that it tends to rotate or twist when a ball strikes the racquet face off center, flattens out, reverses direction and is propelled from the face of the racquet. It is the off-center location of impact that produces forces which tend to rotate the racquet. Obviously, since the racquet face has a diameter which is greater than that of the handle, the torque applied to the wrist due to the off-center impact is magnified. This twisting force is normally transmitted from the racquet, through the wrist and forearm of the user to the elbow, thereby becoming the major contributory factor to the class of ailments known as "tennis elbow". Although the magnitude of the torsional force is dependent upon the mass and velocity of the ball and the displacement of the collision from the central or major axis of the racquet face, the conventional racquet construction in many instances hinders the performance of the racquet and the protection of the user from the stresses induced by off-center impacts.
Another problem encountered when utilizing the conventional racquet is the creation of transverse vibrational motion. It should be noted that the production of transverse vibrations is normally not troublesome when a ball hits the racquet face on-axis or in the center of the "sweet spot". However, when a ball hits the racquet face off-center, complex torsional modes of vibration are produced, substantially inducing stress on the wrist and elbow of the user.
The present invention has resolved the above encountered problems by providing a system of self-adjusting counterbalancing weights, thereby substantially reducing the torsional force and vibrations produced by off-center impacts. The invention further provides a counterbalancing system which may be incorporated into new racquet heads or supplied as an adjunct device which may be added to existing racquet heads, thereby providing maximum performance of the racquet and protection of the user from the stresses induced by off-center impacts.
Accordingly, it is an object of the present invention to provide an apparatus for simultaneously reducing torsional force and vibrations caused by off-center impacts between a ball and the face of a racquet.
It is a further object of the present invention to reduce wrist and elbow strain caused by conventional racquets such that the torsional force applied to the wrist and transmitted to the elbow due to the off-center impact is minimized.
It is another object of the present invention to minimize errors in the trajectory of the ball as it rebounds off the racquet face.
Other objects and various further features of novelty will be pointed out and will occur to those skilled in the art from the following specification when taken in conjunction with the accompanying drawings.